BIOMECHANICS (PART3) Flashcards
what is Biomechanics ?
Biomechanics is the study of human movements, the effect of force and motion on a sport performance.
What are Newton’s laws?
Law of inertia, Law of acceleration and Law of reaction.
What is stated in Newton’s first law?
Law of inertia, A body remains at rest or uniform velocity until an external or unbalanced force acts upon it.
What is stated in Newton’s second law?
Law of acceleration, A body’s rate of change in momentum is proportional to the size of force applies and acts in the same direction as the force applies.
What is stated in Newton’s third law?
Law of Reaction, when 2 body’s come into contact with each other there is an equal and opposite reaction force.
What are the 4 different concepts that can be calculated?
Velocity, Momentum, Acceleration, force.
What is the formula for Velocity and Momentum?
Velocity=displacement/time taken
Momentum=Mass X Velocity
What is the formula for Acceleration and Force?
Acceleraration= (final velocity - initial velocity)/time taken
What are the units for the 4 main concepts that can be calculated?
Velocity= m/s
momentum= kgm/s
Acceleration= m/s/s
Force= Newtons (N)
what is force and its doing?
Essential for motion, external and internal forces act on a body that tend to alter a body’s state of motion.
External force?
is an outside force that acts on the body, e.g. friction, air resistance, weight (gravity), reaction.
Internal force?
Generated from within the body, when the skeletal muscle contract .
example; (100m sprinter contracts rectus femoris to extend knee and gastrocnemous to planter flex the ankle to generate force needed to drive away).
What is Net force and when is Net force = 0?
Net force is the overall motion of the body taking HORIZONTAL and VERTICLE forces into count. Net force = 0 when the overall motions have no change in it and all force are balanced.
When is Net force unbalanced?
Net force is unbalanced when there is change in motion and the external force acting on a body are unbalanced. During this situation of a body there will be acceleration, deceleration, change in shape and direction.
Example of when Net force is balanced and unbalanced.
Net force balanced; in rugby 2 packs are in scrum with equal weight(Net force = 0)
Net force unbalanced; in tennis serve the player generates greater force then needed to over come the tennis ball’s inertia.
how does Analysis through use of technology help sports?
professionals uses it to analyse movement and enhance performance.
What is Limb Kinematics?
Is the study of movements in relation to time and space.
How does Limb kinematics analyse’s movements.
reflective markers are placed on the body’s joints to which can be traced by the infra-red camera’s and convert into digital format. To evaluate the joint and limb efficiency with measurements of bones geometry, displacement, velocity and acceleration in multiple planes of movements.
Disadvantages of limb kinematics.
too expensive.
doesn’t account for individual difference.
Limited to lab conditions
Advantages of Limb kinematics?
Immediate anaylsis recieved
abjective measurements
accurate data
What is force plate?
It can measure ground reaction force of athletes, balancing, running or jumping.
uses transducers to measure the force involved in during motion.
How does force plates work?
upon coming into contact with force plate it will display the time and force that is being applied on a graphical form of computer..
Advantages of force plates?
Reliable results are provided.
Can prevent injuries
Helps with generating the force needed for every contact point e.g. in verticle jump both legs need to generate the same Newtons of force.
Disadvantages of force plate?
Too expensive
limited to lab conditions
maintenance/specialist training required.